A bent piece of an axle or shaft, or an attached arm perpendicular, or nearly so, to the end of a shaft or wheel, used to impart a rotation to a wheel or other mechanical device; also used to change circular into reciprocating motion, or reciprocating into circular motion.

(transitive) To turn by means of a crank. / (intransitive) To turn a crank. / (intransitive, of a crank or similar) To turn. / (transitive) To cause to spin via other means, as though turned by a crank.

(informal) An eccentric, crazy or foolish person. / (informal) Someone addicted to crack cocaine (i.e. a drug addict).

(informal) Eccentric or impractical.

A painful contraction of a muscle which cannot be controlled. / That which confines or contracts. / A clamp for carpentry or masonry.

(intransitive) (of a muscle) To contract painfully and uncontrollably. / (transitive) To affect with cramps or spasms. / (transitive, figuratively) To prohibit movement or expression of.

(archaic) cramped; narrow

(idiomatic) To produce in large volumes mechanically or as if by machine.

(vulgar, slang, derogatory) A person addicted to crack cocaine who finances the habit through prostitution. / (vulgar, slang, derogatory, by extension) Any sexually promiscuous or adulterous woman.

(informal) A beauty treatment for men in which hair is removed from the back, from between the buttocks ("crack") and from the scrotum ("sack").